Protein may protect nerve cells from Huntington's disease

The peptide was effective at stopping Huntington's disease-like symptoms in mice, researchers report.

Stephen Feller

Although Huntington's disease has no cure, researchers at Case
Western Reserve University report a novel peptide they developed stopped
symptoms of the disease in mice. Photo by Tashatuvango/Shutterstock

Researchers
have found a way to prevent a mutant protein from affecting the action
of mitochondria, suggesting a new method of treatment for people with
Huntington's disease, according to a study published in the journal Nature Communications.

Case Western Reserve University researchers
found valosin-containing protein, or VCP, is attracted to cell
mitochondria by the mutant protein, called Huntingtin -- but with a
novel peptide that disrupts the interaction between VCP and the mutant,
Huntington's disease may have its first effective treatment.

Huntington's disease is a genetic disorder,
which causes the mutation of Huntingtin, leading to the degradation and
destruction of nerve cells, progressively limiting a patient's ability
to walk, speak or control their body.

"We found that VCP is a key player in
mitochondria-associated autophagy, a mitochondria self-eating process,"
Dr. Xin Qi, an assistant professor of physiology and biophysics at Case
Western, said in a press release. "Over-accumulation of VCP on
mitochondria thus results in a great loss of mitochondria, which leads
to neuronal cell death due to lack of energy supply."

After the researchers discovered that mice
with mutant huntingtin have mitochondria filled with VCP, like nerve
cells donated by Huntington's patients, the researchers learned
mitochondria interacted with only the mutant version of the protein and
set out finding ways to change it.

By identifying regions of VCP and mutant
huntingtin that were interacting, the researchers were able to design a
peptide to which both VCP and mutant huntingtin bind, allowing
mitochondria in nerve cells to focus on healthier proteins. In
experiments, nerve cells exposed to the peptide were healthier and VCP
did not relocate to mitochondria.

When the peptide was given to mice with
Huntington's-like symptoms, they mice stopped exhibiting the symptoms
and appeared healthy, which "suggests a potential therapeutic option for
treatment of Huntington's disease."

The next step, researchers say, will be to find a way to use the peptide for treatment in humans.